The pharmacological/toxicological effects of nitrofuratoin appear to be caused by "activated" reduced metabolites. Therefore, it is important to be able to quantitatively describe the behavior of this economically important, very effective antibiotic and its reduced metabolites in man. We will use our high pressure liquid chromatographic assays to measure the plasma and urine levels of nitrofurantoin and its two reduced metabolites following IV, oral and oral with food administration in normal volunteers. These plasma and urine levels versus time data will allow us to characterize the absorption, distribution, metabolism and excretion of nitrofurantoin and its metabolites. We will also be able to evaluate the effect of food on the rate and extent of availablity and the magnitude of the first pass metabolism effect. These data will allow us to monitor and adjust dosage levels to maximize therapeutic efficacy and minimize toxicity.